Lawn mowers are known in the art. For example, stand-on mowers are discussed in U.S. Pat. Nos. 6,138,446, 6,390,225, 6,688,089, 6,438,931, 6,189,304, 6,438,930, 6,658,831, 6,560,952, and 5,964,082, the disclosures of all of which are all hereby incorporated herein by reference. Example walk-behind lawn mowers are discussed in U.S. Patent Documents 2005/0126146 and 4,920,733, the disclosures of which are all hereby incorporated herein by reference. Example mower operable by seated occupants are discussed in U.S. Patent Documents 2001/0001170, 2002/0059788, U.S. Pat. Nos. 6,438,930, 6,438,931, 6,688,089, 6,658,831, and 6,560,952, the disclosures of which are all hereby incorporated herein by reference.
FIGS. 1-4 illustrate an example lawn mower operable by a seated and/or standing occupant, from U.S. Pat. No. 6,688,089, the disclosure of which is incorporated herein by reference. The mower of FIGS. 1-3 is a zero radius turning self-propelled power lawn mower. This mower includes first and second hydro pumps for controlling first and second corresponding wheel motors, so that the first and second rear drive wheels 43 may be driven independently in order to conduct zero radius turns as discussed above. The mower further includes: independently drivable rear drive wheels 43; cutter deck assembly 12 below which the cutting blades cut grass; front caster wheels 37; foot platform 9 for supporting feet of a standing or sitting operator; optional seat 1; gas tank supports 80 for supporting respective gas tanks; battery housing structure 81 for housing a battery 30 and which also functions to help support the seat assembly; steering control levers 33-34 (which work in conjunction with rigid hand grip bar 32) which allow the rear drive wheels 43 to be independently drivable in opposite directions at the same time so as to enable the mower to perform zero radius turns about a vertical zero radius turning axis; vertically extending support plates or weldments 14 which support console 36 and handle grips 32-34; and deck lift lever 82 which allows the cutter deck assembly 12 together with the engine deck 31 (the combustion engine is mounted on the engine deck 31) to be raised and lowered together in order to adjust the height of the mower cut. For example, when deck lift lever 82 is pulled upwardly, the cutter deck assembly 12 together with the engine deck 31 (and engine) is raised so as increase the height of the mower cut. Chain linkage 83 suspends the deck assembly 12 and 31 and permits it to be raised and lowered in accordance with the position of lever 82.
When deck lift lever 82 is pulled upwardly in a clockwise pivoting fashion (“clockwise” as defined from the port side of the mower as in FIGS. 2 and 4) by an operator, this causes a rod (not shown) traversing the mower frame to also rotate in a clockwise direction. This rod, attached to deck lift rods 100 on either side of the mower, causes rods 100 to be pulled toward the rear of the mower so that lift brackets pivot counterclockwise about pivot axes 101 in order to lift the cutter deck assembly 12 together with the engine deck 31 and engine upwardly via chains 83 in order to raise the cut of the mower. Since the handle grips 32-34 and weldments 14 are attached to the frame and not the engine or cutter deck(s), the grips 32-34 and weldments 14 do not move up/down along with the cutter deck assembly 12, engine, and engine deck 31. In a similar manner, when lever 82 is lowered from a locked position, the weight of the deck assemblies and engine causes the illustrated brackets to rotate clockwise (“clockwise” as defined in, for example, FIG. 2) about axes 101 and rods 100 to move in a forward direction so that the cutter deck assembly 12 is lowered along with the engine deck 31 and engine. In this respect, control arms 130 (see FIG. 4) maintain the lateral position of the cutter deck assembly 12 and engine deck 31 (and the engine) during lower/raising by the deck lift system. Control arms pivot about pivot axis 91 during raising and lower of the decks, and tabs 131 are provided for supporting the pivot axis area.
As review of U.S. Pat. No. 6,688,089 will show that the tractor frame (and thus the handle controls and vertical weldments supported thereby) does not move up/down along with the decks. FIG. 4 illustrates that the tractor frame includes cross member or front wall 123 that is shaped so as to include approximately parallel portions 123a and 123b that are connected by angled portion 123c. The presence of angled portion 123c enables portions 123a and 123b to be approximately parallel to one another yet offset from one another thereby creating space 123d above angled portion 123c where the rear edge of engine deck 31 can move up and down relative to the tractor frame during cutting height adjustment initiated by the deck lift system. In other words, the presence of angled portion 123c creates space 123d so that the space above the toes of the operator (the toes would be at area 123e) may be used for enabling the engine deck to move up/down relative to the frame.
Further details of the mower of FIGS. 1-4 may be found in U.S. Pat. No. 6,688,089, incorporated herein by reference. While the mower of FIGS. 1-4 is excellent in many respects, systems therein may be subject to improvement in certain instances.